At least 27 killed in English Channel's worst migrant disaster to date, but even death won't deter the desperate

London - An investigation was underway Thursday morning after at least 27 migrants died when their small boat capsized in the English Channel. The boat sank soon after setting off from the coast of northern France, packed with people hoping to make the short, but very dangerous 21-mile crossing to England. It's a gamble that has claimed dozens of lives this year – and one that more people have taken and continue to take in 2021 than ever before.

The capsize on Wednesday was the biggest single loss of migrant life in the Channel, one of the world's busiest shipping lanes, since record keeping began in 2014, according to the International Organization for Migration.

As CBS News correspondent Imtiaz Tyab reports, it is a journey that only the most desperate people would even consider making on a tiny, overloaded boat.

Images taken on Wednesday, before the capsize was discovered by a French fishing crew, show at least one boat being pushed out to sea as French police look on.

Men, women and children board inflatable dinghies every day to attempt to cross the English Channel before the bitterness of winter sets in.

Five women and a little girl were among those killed in Wednesday's disaster.

"There were bodies floating in the water, it was very shocking to see," said French lifeboat rescuer Charles Devos. "We recovered six people. All dead."

Politicians on both sides of the Channel say people-smugglers are to blame.

"Now is the time for us all to step up, to work together, to do everything we can to break these gangs who are literally getting away with murder," said British Prime Minister Boris Johnson.

Both his government and that of French President Emmanuel Macron have expressed their horror at the deaths and vowed to cooperate to stop the smugglers. But British-French relations have been difficult since the U.K. voted to leave the European Union, and there's a trust deficit.

Migrant rights groups, meanwhile, say it's the French and British governments who helped create this crisis – France, with the brutal conditions in its migrant camps, and Britain by limiting the legal routes for asylum seekers to enter the U.K.

Combined, they are circumstances that push the most vulnerable people, fleeing war, poverty and famine, to risk it all.

More migrant boats were seen leaving the French coast on Thursday morning.

Five suspected traffickers have been arrested in France in connection with the sinking on Wednesday, but until Britain and France can come up with meaningful solutions to the crisis, the grim reality is that more people will likely lose their lives trying to cross the Channel for what they hope is a better life.